net: bridge: rearrange flood vs unicast receive paths

This patch removes one conditional from the unicast path by using the fact
that skb is NULL only when the packet is multicast or is local.
Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/bridge/br_input.c

@@ -134,10 +134,10 @@ int br_handle_frame_finish(struct net *net, struct sock *sk, struct sk_buff *skb
 	struct net_bridge_port *p = br_port_get_rcu(skb->dev);
 	const unsigned char *dest = eth_hdr(skb)->h_dest;
 	struct net_bridge_fdb_entry *dst = NULL;
+	bool mcast_hit = false, unicast = true;
 	struct net_bridge_mdb_entry *mdst;
 	struct net_bridge *br;
 	struct sk_buff *skb2;
-	bool unicast = true;
 	u16 vid = 0;
 
 	if (!p || p->state == BR_STATE_DISABLED)
@@ -177,30 +177,29 @@ int br_handle_frame_finish(struct net *net, struct sock *sk, struct sk_buff *skb
 		if ((mdst || BR_INPUT_SKB_CB_MROUTERS_ONLY(skb)) &&
 		    br_multicast_querier_exists(br, eth_hdr(skb))) {
 			if ((mdst && mdst->mglist) ||
-			    br_multicast_is_router(br))
+			    br_multicast_is_router(br)) {
 				skb2 = skb;
-			br_multicast_forward(mdst, skb, skb2);
-			skb = NULL;
-			if (!skb2)
-				goto out;
+				br->dev->stats.multicast++;
+			}
+			mcast_hit = true;
 		} else {
 			skb2 = skb;
+			br->dev->stats.multicast++;
 		}
 		unicast = false;
-		br->dev->stats.multicast++;
 	} else if ((dst = __br_fdb_get(br, dest, vid)) && dst->is_local) {
-		skb2 = skb;
 		/* Do not forward the packet since it's local. */
-		skb = NULL;
+		return br_pass_frame_up(skb);
 	}
 
-	if (skb) {
-		if (dst) {
-			dst->used = jiffies;
-			br_forward(dst->dst, skb, skb2);
-		} else {
+	if (dst) {
+		dst->used = jiffies;
+		br_forward(dst->dst, skb, skb2);
+	} else {
+		if (!mcast_hit)
 			br_flood_forward(br, skb, skb2, unicast);
-		}
+		else
+			br_multicast_forward(mdst, skb, skb2);
 	}
 
 	if (skb2)